"(www.nature.com, Leila Haghighat, 18 April 2012) Three separate studies in mice show normal function can be restored to hair, eye and heart cells.
At the turn of the twentieth century, the promise of regenerating damaged tissue was so far-fetched that Thomas Hunt Morgan, despairing that his work on earthworms could ever be applied to humans, abandoned the field to study heredity instead. Though he won the Nobel Prize in 1933 for his work on the role of chromosomes in inheritance, if he lived today, the advances in regenerative medicine may have tempted him to reconsider.
Three studies published this week show that introducing new cells into mice can replace diseased cells - whether hair, eye or heart - and help to restore the normal function of those cells. These proof-of-principle studies now have researchers setting their sights on clinical trials to see if the procedures could work in humans.
'You can grow cells in a Petri dish, but that's not regenerative medicine,' says Robin Ali, a geneticist at University College London, who led the eye study. 'You have to think about the biology of repair in a living system.'
In work published in Nature Communications, Japanese researchers grew different types of hair on nude mice, using stem cells from normal mice and balding humans to recreate the follicles from which hair normally emerges1. Takashi Tsuji, a regenerative-medicine specialist at Tokyo University of Science who led the study, says that the technique holds promise for treating male pattern baldness.
The team used a specialized nylon sheath to guide the hair through the skin layers, enabling it to erupt from the skin of the mice in 94% of all grafts. The hairs took between 2 and 5 weeks to emerge, and behaved as normal: they underwent normal growth cycles and established connections to the muscles and nerves underneath the skin. The hairs also lifted up from the skin in response to acetylcholine, a neurotransmitter known to cause hairs to stand on end..."